contrib/undumprevlog

ui: remove unreachable branches and function calls from write() (issue6059)

This is at least faster than ui.write() of 4.8.2.

  $ HGRCPATH=/dev/null hg files -R mozilla-central --time >/dev/null
  4.8.2:  time: real 2.340 secs (user 2.310+0.000 sys 0.020+0.000)
  4.9rc0: time: real 2.580 secs (user 2.550+0.000 sys 0.020+0.000)
  this:   time: real 2.230 secs (user 2.210+0.000 sys 0.020+0.000)

Maybe the formatter should own a resolved write() function because it will
just call dest.write(msg) most of the time, but that would be too much for
stable.

#!/usr/bin/env python
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump

from __future__ import absolute_import, print_function

import sys
from mercurial import (
    encoding,
    node,
    pycompat,
    revlog,
    transaction,
    vfs as vfsmod,
)
from mercurial.utils import (
    procutil,
)

for fp in (sys.stdin, sys.stdout, sys.stderr):
    procutil.setbinary(fp)

opener = vfsmod.vfs(b'.', False)
tr = transaction.transaction(sys.stderr.write, opener, {b'store': opener},
                             b"undump.journal")
while True:
    l = sys.stdin.readline()
    if not l:
        break
    if l.startswith("file:"):
        f = encoding.strtolocal(l[6:-1])
        r = revlog.revlog(opener, f)
        pycompat.stdout.write(b'%s\n' % f)
    elif l.startswith("node:"):
        n = node.bin(l[6:-1])
    elif l.startswith("linkrev:"):
        lr = int(l[9:-1])
    elif l.startswith("parents:"):
        p = l[9:-1].split()
        p1 = node.bin(p[0])
        p2 = node.bin(p[1])
    elif l.startswith("length:"):
        length = int(l[8:-1])
        sys.stdin.readline() # start marker
        d = encoding.strtolocal(sys.stdin.read(length))
        sys.stdin.readline() # end marker
        r.addrevision(d, tr, lr, p1, p2)

tr.close()